Hybrid turbine nozzle

Abstract

A turbine nozzle apparatus for a gas turbine engine includes: an annular inner band; an annular outer band circumscribing the inner band; a plurality of airfoil-shaped structural vanes extending between and interconnecting the inner band and the outer band; and a plurality of airfoil-shaped non-structural vanes extending between the inner band and the outer band, each non-structural vane having a root end received by the inner band and a tip end received by the outer band, such that each non-structural vane is free to move to a limited degree relative to the inner and outer bands.

What is claimed is: 
     
         1 . A turbine nozzle apparatus for a gas turbine engine, comprising:
 an annular inner band;   an annular outer band circumscribing the inner band;   a plurality of airfoil-shaped structural vanes extending between and interconnecting the inner band and the outer band; and   a plurality of airfoil-shaped non-structural vanes extending between the inner band and the outer band, each non-structural vane having a root end received by the inner band and a tip end received by the outer band, such that each non-structural vane is free to move to a limited degree relative to the inner and outer bands.   
     
     
         2 . The apparatus of  claim 1  wherein one of the inner and outer bands includes a plurality of blind pockets, each blind pocket receiving one of the ends of the non-structural vanes. 
     
     
         3 . The apparatus of claim wherein one of the inner and outer bands includes:
 a plurality of spaced-apart apertures formed therein; and   a cover received in each aperture, the aperture including at least one blind pocket, each blind pocket receiving one of the ends of the non-structural vanes.   
     
     
         4 . The apparatus of  claim 1  wherein one of the inner and outer bands includes at least one split section comprising:
 a forward segment that is integral to adjacent sections of the band, the forward segment defining a forward section of at least one airfoil-shaped blind pocket; and 
 an aft segment mating with the forward segment along a splitline, the aft segment defining an aft section at least one airfoil-shaped blind pocket, wherein the blind pocket receives one of the ends of the non-structural vanes. 
 
     
     
         5 . The apparatus of  claim 1  wherein the non-structural vanes comprising a ceramic matrix composite. 
     
     
         6 . The apparatus of  claim 1  wherein the structural vanes comprise a metallic alloy. 
     
     
         7 . The apparatus of  claim 1  wherein:
 the inner band includes a plurality of blind root pockets, each root pocket receiving one of the root ends of one of the non-structural vanes; and 
 the outer band includes:
 a plurality of spaced-apart apertures formed therein; and 
 a cover received in each aperture, the aperture including a plurality of blind pockets, each blind pocket receiving one of the tip ends of one of the non-structural vanes. 
 
 
     
     
         8 . The apparatus of  claim 1  wherein:
 the outer band includes a plurality of blind tip pockets, each tip pocket receiving one of the tip ends of one of the non-structural vanes; and 
 the inner band includes at least one split section comprising:
 a forward segment that is integral to adjacent sections of the inner band, the forward segment defining forward sections of a plurality of airfoil-shaped blind pockets; and 
 an aft segment mating with the forward segment along a splitline, the aft segment defining aft sections of a plurality of airfoil-shaped blind pockets, wherein each of the blind pockets receives one of the root ends of the non-structural vanes. 
 
 
     
     
         9 . The apparatus of  claim 1  wherein the inner and outer bands are divided into a plurality of segments. 
     
     
         10 . A method of assembling a turbine nozzle for a gas turbine engine, comprising:
 providing an annular inner band, an annular outer band circumscribing the inner band, and a plurality of airfoil-shaped structural vanes extending between and interconnecting the inner band and the outer band;   inserting an airfoil-shaped non-structural vane through an opening formed in one of the inner and outer bands; and   closing the opening, such that the non-structural vanes extend between the inner band and the outer band, each non-structural vane having a root end received by the inner band and a tip end received by the outer band, such that each non-structural vane is free to move to a limited degree relative to the inner and outer bands.   
     
     
         11 . The method of  claim 10  wherein one of the inner and outer bands includes a plurality of blind pockets, each blind pocket receiving one of the ends of the non-structural vanes. 
     
     
         12 . The method of  claim 10  wherein one of the inner and outer bands includes:
 a plurality of spaced-apart apertures formed therein; and 
 a cover received in each aperture, the aperture including at least one blind pocket, each blind pocket receiving one of the ends of the non-structural vanes. 
 
     
     
         13 . The method of  claim 10  wherein one of the inner and outer bands includes at least one split section comprising:
 a forward segment that is integral to adjacent sections of the band, the forward segment defining a forward section of at least one airfoil-shaped blind pocket; and 
 an aft segment mating with the forward segment along a splitline, the aft segment defining an aft section at least one airfoil-shaped blind pocket, wherein the blind pocket receives one of the ends of the non-structural vanes. 
 
     
     
         14 . The method of  claim 10  wherein the non-structural vanes comprising a ceramic matrix composite. 
     
     
         15 . The method of  claim 10  wherein the structural vanes comprise a metallic alloy. 
     
     
         16 . The method of  claim 10  wherein:
 the inner band includes a plurality of blind root pockets, each root pocket receiving one of the root ends of one of the non-structural vanes; and 
 the outer band includes:
 a plurality of spaced-apart apertures formed therein; and 
 a cover received in each aperture, the aperture including a plurality of blind pockets, each blind pocket receiving one of the tip ends of one of the non-structural vanes. 
 
 
     
     
         17 . The method of  claim 10  wherein:
 the outer band includes a plurality of blind tip pockets, each tip pocket receiving one of the tip ends of one of the non-structural vanes; and 
 the inner band includes at least one split section comprising:
 a forward segment that is integral to adjacent sections of the inner band, the forward segment defining forward sections of a plurality of airfoil-shaped blind pockets; and 
 an aft segment mating with the forward segment along a splitline, the aft segment defining aft sections of a plurality of airfoil-shaped blind pockets, wherein each of the blind pockets receives one of the root ends of the non-structural vanes. 
 
 
     
     
         18 . The method of  claim 10  wherein the inner and outer bands are divided into a plurality of segments.